The three main explanations making the rounds for why airport security waits have gotten out of control in the U.S. this spring have been:

Lots more people are flying.

Budget cutbacks have forced the Transportation Security Administration to make do with fewer screeners.

The TSA is a bungling bureaucracy.

There is surely something to all three of these, and it’s easy to find statistical evidence for the first two. After a long, recession-induced slump, the number of U.S. air travelers set a monthly record of 75.6 million last July (the previous high was in July 2007), according to the Bureau of Transportation Statistics, and passenger traffic might break that record again this summer. Meanwhile, the number of security screeners, measured once a year by the Bureau of Labor Statistics, fell from 47,200 in 2012 to 41,820 in May 2015.

Still — in part because growth in air travel, tight federal budgets and bureaucratic bungling all seem somewhat inevitable at this point — it’s important to look for other causes of the security-line bottleneck. And yes, people have been looking, and finding.

Bloomberg View’s editorial board argues, for example, that the TSA’s list of items that are prohibited on planes is a big part of the problem. The list is outdated and largely nonsensical, yet ninnies in Congress object to any proposed change. It’s a classic case of “security theater” trumping actual security.
Another angle, pushed this month by Homeland Security Secretary Jeh Johnson and Democratic Senators Ed Markey and Richard Blumenthal, is that the fees airlines charge for checked baggage are causing travelers to bring more, bigger carry-ons that slow security checks. My initial thought was that these bag charges couldn’t be the problem because they’ve been around for years. But it turns out that American became the first legacy carrier to impose a fee for checking even one bag in May 2008, just as air travel was beginning a steep decline. Now that passenger numbers are finally setting new records again, it’s not unreasonable to think that the baggage charges are at least part of the security-line problem.

Finally, there’s what I think may be the most interesting culprit of all: A seemingly good idea for reducing security waits that at this point is probably making them longer. This would be TSA Pre-Check, the streamlined screening program (you can keep your shoes and light jacket on and your laptop and toiletries in your luggage, and usually get to go through a metal detector instead of a full-body scanner) that was rolled out in 2011 and expanded in 2013 as what then-TSA chief John Pistole called the “happy lane.” As Bloomberg’s Alan Levin and Jeff Plungis reported Thursday:

For the small portion of travelers now in the program that provides access to short lines, it may fit John Pistole’s description. But for passengers who don’t participate, it has contributed to security screening delays and growing tensions at airports because far fewer people signed up than the agency projected.

Devoting staff and machines to Pre-Check screening lanes with hardly anybody going through them means taking them away from general screening lanes with lots of people going through them. Some airport TSA managers have reacted to the crush of traffic this spring by shutting down Pre-Check lanes, which is understandable but leaves no one happy. I experienced this early one Saturday morning this month at Houston’s George Bush Intercontinental Airport. Those of us with the telltale checkmark on our boarding passes got to stand in a separate, shorter line to get our IDs checked, but were then put in the same security screening line as everybody else. When we finally got close to the machines, I told a TSA worker that I had Pre-Check and asked if I needed to take my laptop out or my shoes off. Laptop comes out but shoes can stay on, she said, then allowed me to cut in front of several people and go through the metal detector instead of the scanner — without ever looking at my boarding pass to verify that I was in fact Pre-Checked. Now that’s security!

The problem, as Levin and Plungis report, is that the TSA expected to have 25 million people in the Pre-Check program by now, but so far only 2.8 million have signed up. Another 6.7 million get Pre-Check treatment because they belong to other trusted traveler programs such as Global Entry.

Why have so few people signed up? One reason is surely inadequate marketing by the TSA, airports and airlines. Hancock International Airport in Syracuse, New York, offers a seemingly rare example of how to do it right. Forty percent of those who fly out of the airport are enrolled in Pre-Check, executive director Christina Callahan testifiedThursday before a House Homeland Security subcommittee:

We believe that this is the result of having an enrollment center in the terminal, our efforts to educate the public on the benefits of Pre-Check, and while seemingly insignificant, the airport’s offer to validate parking for Pre-Check applicants.

Even with free parking, though, signing up for Pre-Check takes work. The process involves fingerprinting, a brief in-person interview, an $85 fee and showing either a passport or a driver’s license plus birth certificate. I signed up for Pre-Check on a whim a few years ago when I was waiting at New York’s JFK International for a flight to Brazil and thus had my passport with me. Most U.S. air travelers aren’t headed overseas, and don’t carry their birth certificates with them. So signing up usually involves planning ahead and making an appointment at a Pre-Check enrollment center, which isn’t so bad if you happen to live in Manhattan, where there are three, but isn’t quite so convenient in much of the rest of the country.

If you fly often, you know that this is all worth it. You are also well aware that Pre-Check exists — although the practice of frequently extending Pre-Check status to those who hadn’t signed up for it, which was discontinued last year after a Homeland Security Inspector General’s report deemed it an “unacceptable risk,” may have confused many people about what they had to do to sign up.

For most Americans, though, an airplane flight remains a relatively rare event. A Gallup poll in December found that 55 percent of respondents hadn’t been on an airplane in the previous 12 months, and only 19 percent had been on three plane trips or more. So lots of air travelers are discovering only now that there’s this thing they could have done to make their security wait shorter.

This spring’s big lines, and the publicity they’ve gotten, have led to a doubling in the pace of Pre-Check signups. Maybe, eventually, it will work as planned. Until then, though, it appears to be one more reason why going to the airport will be a pain this summer.

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